Summit Entertainment scored its best-ever opening per-screen average over the Sept. 21-23 weekend, with teen-targeted “The Perks of Being a Wallflower” averaging $57,090 from four locations in New York and Los Angeles, besting even those turned in by the “Twilight” heavyweights.“Perks,” which totaled $228,359 over the Sept. 21-23 frame, earned the fifth-highest per-screen debut per this year, behind “The Master” ($147,262), “Moonrise Kingdom” ($130,749), “To Rome With Love” ($72,272) and “Sleepwalk With Me” ($68,801). As for Summit’s previous best debut per-screen averages, “Wallflower” bested “The Ghost Writer,” which averaged $45,752 from four locations in 2010. The distrib’s 2009 Oscar winner “The Hurt Locker” averaged $36,338 during its first frame, followed closely that same year by the second “Twilight” pic, “New Moon,” at $35,497 in uber-wide release. The per-screen success for “Perks” should translate into a solid expansion, based on upbeat reviews and word-of-mouth. By comparison, “The Master,” which scored the best-ever opening per screen for a live-action film, struggled to develop legs as the Weinstein Co. expanded the film aggressively to 788 locations during the pic’s second frame. The highbrow art film received middling, at best, exit polls between the coasts; “Perks” should score as a more general crowdpleaser, employing a slower Stateside rollout. Summit expands “Perks” this week to 102 total locations in cities including Chicago, Dallas, Houston, Miami and Washington, D.C.